William Shatner felt a sense of "grief" when he went up into space.

The 91-year-old actor - who is known for his starring role as Captain Kirk in the 'Star Trek' franchise - became the oldest person ever to reach space when he blasted off on Jeff Bezos's New Shepard NS-18 rocket in October 2021 but has revealed that the experience wasn't as "beautiful" as he thought it was going to be.

He said: "I had thought that going into space would be the ultimate catharsis of that connection I had been looking for between all living things—that being up there would be the next beautiful step to understanding the harmony of the universe.I discovered that the beauty isn’t out there, it’s down here, with all of us. Leaving that behind made my connection to our tiny planet even more profound. It was among the strongest feelings of grief I have ever encountered. The contrast between the vicious coldness of space and the warm nurturing of Earth below filled me with overwhelming sadness. Every day, we are confronted with the knowledge of further destruction of Earth at our hands: the extinction of animal species, of flora and fauna…things that took five billion years to evolve, and suddenly we will never see them again because of the interference of mankind. It filled me with dread. ."

The 'Boston Legal' star went on to compare the feeling of being in space to being "at a funeral" and explained that he was experiencing a common feeling known as the 'Overview Effect.'

Writing in his new autobiography 'Boldly Go: Reflections on a Life of Awe and Wonder', he added: "My trip to space was supposed to be a celebration; instead, it felt like a funeral. It is called the ‘Overview Effect’ and is not uncommon among astronauts, including Yuri Gagarin, Michael Collins, Sally Ride, and many others. Essentially, when someone travels to space and views Earth from orbit, a sense of the planet’s fragility takes hold in an ineffable, instinctive manner. Author Frank White first coined the term in 1987: ‘There are no borders or boundaries on our planet except those that we create in our minds or through human behaviors. All the ideas and concepts that divide us when we are on the surface begin to fade from orbit and the moon. The result is a shift in worldview, and in identity."